The Fig-Like hierarchical Double-Shelled hollow TiN particles as sulfur host for Lithium-Sulfur batteries.

Lithium-sulfur battery(LSB)'s commercial manufacturing has been mainly retarded by the "shuttle effect" and low electrical conductivity of polysulfides (LiPSs). Designing a cathode with hollow and hierarchically porous structures was expected to solve the above problems. Herein, a kind of TiN particles with the hierarchical hollow double-shelled structures was synthesized and applied to cathodes of LSB. The Fig-like hollow TiO2 particles (FHTiO2s) were firstly synthesized by the hard-template method. Subsequently, the Fig-like hierarchical hollow double-shelled TiN particles (FHTiNs) were synthesized by the template-free sequential transformation and separation approach (STSA). It was verified that the heating temperature and time were key parameters. Special Fig-like double-shell hollow structures could greatly increase the loading of S, and the excellent initial capacity of FHTiNs cathodes was up to 1159 mAh/g. On the one hand, the Fig-like framework in internal cavity and double-shell structures could promote the ultrahigh specific surface area, and the adsorption to LiPSs was improved by increasing active sites; On the other hand, the shuttle effect of LiPSs was weakened by the fig-like framework and double-shell structures, which slowed down the massive dissolution of sulfur in the electrolyte. As a result, the pleasant rate performance of FHTiNs cathodes was up to 400 mAh/g at 5C. This novel structures and synthesis method provided a new strategy for the designing of LSB cathodes.

An unsymmetrical binuclear iminopyridine-iron complex and its catalytic isoprene polymerization.

A series of chloride-bridged unsymmetrical mixed Fe(ii)-HS/Fe(ii)-LS binuclear structures has been prepared and characterized. Upon activation with MAO, highly efficient catalytic polymerization of isoprene was achieved, delivering an ultra-high molecular weight (catalyst loading = 2.5 ppm, Mn = 1.8 × 106 g mol-1, Mw/Mn = 1.4).

Janus Polymer Composite Electrolytes Improve the Cycling Performance of Lithium-Oxygen Battery.

The liquid electrolytes in lithium-air (oxygen) batteries are prone to volatilize, leak, flame, and cause uneven deposition of lithium during cycling, which makes the batteries to face serious problems in terms of safety and cycling stability. A novel Janus quasi-solid composite polymer electrolyte was fabricated by perfluorosulfonic acid (Nafion) membranes with tunable thickness and poly(vinylidene fluoride)-hexafluoropropylene (PVDF-HFP). The Nafion membranes not only guarantee the mechanical strength of the composites but also effectively prevent the migration of certain anions and macromolecules. The results indicate that Janus quasi-solid composite polymer electrolytes have excellent thermal stability, high lithium-ion migration number, and wide electrochemical window. Lithium-oxygen batteries using the novel quasi-solid composite electrolytes perform lower polarization and better cycling stability. The excellent properties of the quasi-solid composite electrolytes make it one of the effective materials for improving the cycling stability of lithium-air (oxygen) batteries.

A facile approach to preparation of silica double-shell hollow particles, and their application in gel composite electrolytes.

Double-shell hollow particles (DSHPs) have attracted significant attention due to their diverse potential applications. DSHPs are usually obtained by multi-step sacrificial template method which is tedious and inefficient. In this work, a facile synthesis of silica DSHPs has been developed via a novel one-step template method, which is using single-hole hollow particles (SHHPs) as the templates. The shapes and internal structures of the DSHPs were determined by SEM and TEM, and the average diameters of inner and outer shells were about 0.6 and 1.6 µm, respectively. According to FTIR analyses, the compositions of silica DSHPs were identified as well. Furthermore, the silica DSHPs was applied to Li-ion batteries as a modifier of gel polymer electrolyte (GPEs), and the results showed that the gel composite electrolytes (GCEs) could display higher capability, higher ionic conductivity and better rate performance at high current density for GCEs-cell. Properties of the silica DSHPs such as larger specific surface area, more porous structures and Lewis acid-base effect were important for high-performance Li-ion batteries.

A mesoporous tungsten carbide nanostructure as a promising cathode catalyst decreases overpotential in Li-O2 batteries.

Lithium-oxygen (Li-O2) batteries as promising energy storage devices possess high gravimetric energy density and low emission. However, poor reversibility of electrochemical reactions at the cathode significantly affects the electrochemical properties of nonaqueous Li-O2 batteries, and low charge-discharge efficiency also results in short cycle-life. In this work, functional air cathodes containing mesoporous tungsten carbide nanoparticles for improving the reversibility of positive reactions in Li-O2 cells are designed. Mesoporous tungsten carbides are synthesized with mesoporous carbon nitride as the reactive template and carbon source. And mesoporous tungsten carbides in cathode materials display better electrochemical performance in Li-O2 cells in comparison with mesoporous carbon nitride and hard carbon. Tungsten carbide-1 (WC-1) with larger specific surface area promotes reversible formation and decomposition of Li2O2 at the cathode and lower charge overpotential (about 0.93 V) at 100 mA g-1, which allows the Li-O2 cell to run up to 100 cycles. In addition, synergistic interaction between WC-1 and LiI could further decrease the charging overpotentials of Li-O2 cells and improve the charge-discharge performances of the Li-O2 cells. These results indicate that mesoporous electrocatalysts can be utilized as promising functional materials for Li-O2 cells to decrease overpotentials.

Preparation and properties of ion-imprinted hollow particles for the selective adsorption of silver ions.

Four kinds of silver ion-imprinted particles (Ag-IIPs) with different morphologies were prepared by the surface ion-imprinting technology (SIIT) and were used for the selective removal and concentration of silver ions from wastewater. The favorable adsorptivity and selectivity of Ag-IIPs for Ag(+) were confirmed by a series of adsorption experiments at a suitable pH value. The adsorption mechanism was elucidated by analyzing the adsorption isotherms, adsorption thermodynamics, and adsorption kinetics systematically. The Ag(+) adsorption onto the Ag-IIPs was well-described by the Langmuir isotherm model, and it was likely to be a monolayer chemical adsorption. This conclusion was also confirmed by the thermodynamic parameters. Moreover, the adsorption kinetics indicated that the adsorption rate would be controlled jointly by the intraparticle diffusion and the inner surface adsorption process, and the latter process was generally associated with the formation and breaking of chemical bonds. Finally, the effects of different morphologies of the Ag-IIPs for Ag(+) adsorption were also investigated. In aqueous solution, the adsorptivity of the Ag(+) ion-imprinting single-hole hollow particles (Ag-IISHPs) for Ag(+) was highest (80.5 mg g(-1)) because of a specific morphology that features a single hole in the shell. In an oil-water mixture, Ag(+) in the water phase could be adsorbed efficiently by the Ag(+) ion-imprinting Janus hollow particles (Ag-IIJHPs), with emulsifiability originating from the Janus structure.

Preparation, characterization, and properties of hollow Janus particles with tailored shapes.

As compared to the traditional solid Janus particles, the hollow Janus particles have inspired growing interests due to their diverse potential applications. Herein, the novel hollow Janus particles with elephant trunk-like and acorn-like shapes were prepared by seed emulsion polymerization. In contrast to traditional template methods, the hollow structure was obtained during the preparation by one-step swelling method. The shapes and internal structures of hollow Janus particles were confirmed, and the compositions were identified too. Some critical influences on the morphology control were investigated, that is, the surface modification, the amount of surfactant, and cross-linking agent concentrations. It was inferred that the balance of hydrophilicity and hydrophobicity and the effective phase separation were important for preparing the hollow Janus particles with tailored shapes. Finally, amphiphilic properties of hollow Janus particles were demonstrated by emulsifying oil-water mixture.

[Study on the serotype, virulence genes and pulsed field gel electrophoresis molecular typing of Vibrio parahaemolyticus isolated from clinical patients].

OBJECTIVE: To investigate the serotype virulence genes and molecular typing characteristics of Vibrio Parahaemolyticus isolated from diarrhea samples among 2007 -2012. METHODS: The serotype was detected by using serological agglutination test. Thermo-stable direct hemolysin (tdh) and tdh-related hemolysin (trh) were detected by using real time PCR methods. 56 strains 03:K6 were analyzed for molecular typing by pulsed field gel electrophoresis(PFGE). RESULTS: (1) There are 14 serotypes, including 03: K6 (114,67.9%),04: K8 (25,14.9%), 03: K29 (6,3.6%) and et al. Compared with the serotypes of strains from food poison, these from sporadic cases with diarrhea were different, but the main serotype was also 03:K6. (2) There are 4 types of virulence genes, including tdh+ trh- (161, 95.8%), tdh+ trh+ (3,1.8%), tdh- trh+ (1, 0.6%) tdh- trh- (3, 1.8%). Compared with the virulence genes of strains from food poison, these from sporadic cases with diarrhea were different, but the main virulence gene was also tdh+ trh-. 3,56 strains belonged to 15 PFGE strips and the similar degree is higher than 86%. 10 patterns (P1-P4, P6, P7, P9, P10, P12, P15) had at lest two strains. CONCLUSION: The most V. Parahaemolyticus isolated from clinical patients was 03: K6 and tdh+ trh-. PFGE strips of V. Parahaemolyticus of 03: K6 from clinical patients exhibited a high degree of similarity, and correlation was found among strains.